Compound balde of a fan

ABSTRACT

The invention relates to a compound blade and a fan installed with it. The compound blade is composed of at least a flexible layer and a rigid layer, with the rigid layer smaller than the flexible layer. So the edge of the compound blade is only formed of the flexible layer after the flexible layer combined with the rigid layer. A fan installed with the compound blade can not only run without danger because of the flexible layer, but also run as efficiently as a general one owing to the rigid layer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a fan, particularly to one installed with compound blades.

2. Description of the Prior Art

Although air conditioners are generally used in homes owing to progressive technique greatly promoting human living standard, electric fans are still popularly needed on account of low price, consuming less power, being plugged at once to work without other installation, and being moved with ease.

Commonly, the conventional fans have rigid blades surrounded by a protective hood employed to protect the blades and keep them from hurting users. The protective hood has long been made of metal almost in a same manner, manufactured with a complicated art, not durable to corrosion. Thus a novel plastic hood has been given out in recent years, with lots of advantages in comparison to the metallic one. However, it is more unsafe than the metallic one in practice. Moreover, in order to achieve a more aesthetic appearance, some plastic hoods are so simplified that they may allow a hand or other large objects to pass through to get hurt by the blades, with a downgraded safety.

SUMMARY OF THE INVENTION

The object of this invention is to offer a compound blade of a fan, able to step up security of the fan without sacrificing its efficiency.

The compound blade is composed of at least a flexible layer and a rigid layer, with the rigid layer smaller than the flexible layer. So the edge of the compound blade is only formed of the flexible layer after the flexible layer combined with the rigid layer.

Another object of this invention is to offer a fan installed with the compound blade, which are respectively composed of at least a flexible layer and a rigid layer, with the rigid layer smaller than the flexible layer. So the edge of the compound blade is only formed of the flexible layer after the flexible layer combined with the rigid layer.

Therefore, a fan installed with the compound blade can not only run without danger because of the flexible layer fully surrounding the edge of the compound blade, but also run as efficiently as a general one owing to the rigid layer.

BRIEF DESCRIPTION OF DRAWINGS

This invention is better understood by referring to the accompanying drawings, wherein:

FIG. 1 is a perspective view of a preferred embodiment of a compound blade of a fan in the present invention;

FIG. 2 is an exploded perspective view of the preferred embodiment of the compound blade of a fan in the present invention;

FIG. 3 is a perspective view of the preferred embodiment of the compound blade of a fan in the present invention, showing a flexible layer being taken off;

FIG. 4 is a cross-sectional perspective view of the preferred embodiment of the compound blade of a fan in the present invention; and

FIG. 5 is a magnified view of a section marked “A” in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1, a preferred embodiment of a compound blade 1 of a fan in the present invention has a same perspective view as the conventional one does, formed as a thin plate with a certain curve. The compound blade 1 has two installing holes 10 bored in one side and a soft flexible circumference.

As shown in FIGS. 2, 4 and 5, the compound blade 1 is composed of a first flexible layer 11, a second flexible layer 12 and a rigid layer 13. The first flexible layer 11 and the second flexible layer 12 have the same shape and size, both made of EVA (Ethylene-vinyl acetate copolymer), with an approximate thickness of 1.5 mm. The rigid layer 13 is made of PP (polypropylene), with an approximate thickness of 0.5 mm. Next, as shown in FIG. 3, the rigid layer 13 has a size smaller than that of the first flexible layer 11 and the second flexible layer 12, so that the rigid layer 13 can be totally covered between the first flexible layer 11 and the second flexible layer 12. That is, the circumferential edge of the compound blade 1 is merely formed of EVA without PP of the rigid layer 13, able to prevent a hand from dangerously hurt in case of being incautiously hit by the compound blade 1 while rotating. And, with the rigid layer 13 to reinforce the compound blade 1 with strength, a fan with the compound blade 1 can run much more efficiently than that with only flexible blade.

The first flexible layer 11, the second flexible layer 12 and the rigid layer 13 can be combined together by adhesive, supersonic welding, sewing with silk or riveting. The preferred choice is glue or a double-sided tape.

Each of the first flexible layer 11 and the second flexible layer 12 is bored with three installing holes 10 corresponding to one another. The rigid layer 13 is bored with two installing holes 10 corresponding to two of the installing holes 10 of the first flexible layer 11 and the second flexible layer 12.

It should be noticed that the thicknesses of the first flexible layer 11, the second flexible layer 12 and the rigid layer 13 mentioned previously are just examples, not limited. Practically, the first flexible layer 11 and the second flexible layer 12 can have a thickness ranging from 0.5 mm to 5 mm, with a preference ranging from 1 mm to 2 mm. The rigid layer 13 can have a thickness ranging from 0.2 mm to 3 mm, with a preference ranging from 0.3 mm to 2 mm.

Furthermore, the compound blade 1 can also include only one flexible layer and a rigid layer, able to achieve an effect needed basically. Yet the preference is the embodiment described above.

While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention. 

1. A compound blade of a fan comprising at least a flexible layer and a rigid layer, said rigid layer having a size smaller than said flexible layers so that said compound blade has a soft edge after said flexible layer combined with said rigid layer.
 2. The compound blade of a fan as claimed in claim 1, wherein said compound blade is composed of a first flexible layer, a second flexible layer and a rigid layer, with said rigid layer combined between said first flexible layer and said second flexible layer.
 3. The compound blade of a fan as claimed in claim 1, wherein said flexible layer have a thickness ranging from 0.5 mm to 5 mm.
 4. The compound blade of a fan as claimed in claim 3, wherein said flexible layers have a thickness ranging from 1 mm to 2 mm.
 5. The compound blades of a fan as claimed in claim 1, wherein said rigid layer has a thickness ranging from 0.2 mm to 3 mm.
 6. The compound blades of a fan as claimed in claim 5, wherein said rigid layer has a thickness ranging from 0.3 mm to 2 mm.
 7. The compound blades of a fan as claimed in claim 1, wherein said flexible layers and said rigid layer are combined together by adhesive.
 8. The compound blades of a fan as claimed in claim 1, wherein said flexible layers and said rigid layer are combined together by supersonic welding.
 9. The compound blades of a fan as claimed in claim 1, wherein said flexible layers and said rigid layer are combined together by sewing with silk.
 10. The compound blades of a fan as claimed in claim 1, wherein said flexible layers and said rigid layer are combined together by riveting.
 11. The compound blades of a fan as claimed in claim 7, wherein said flexible layers and said rigid layer are combined together by glue.
 12. The compound blades of a fan as claimed in claim 7, wherein said flexible layers and said rigid layer are combined together by a double-sided tape.
 13. The compound blades of a fan as claimed in claim 1, wherein said flexible layer is bored with three installing holes and said rigid layer is bored with two installing holes corresponding to two of said installing holes of said flexible layer.
 14. (canceled) 